USDA Hardiness Zone 6b

Frost Dates for 47274 — Seymour, Indiana

NOAA 1991–2020 normals from Seymour 2 N, IN (570 ft), 2 miles north.

Updated October 28, 2026

In Seymour, the last spring frost (32°F) is around April 16 in half of years and has passed by May 2 in nine years out of ten. The first fall frost comes around October 21, as early as October 7 one year in ten, leaving a typical freeze-free season of 187 days (NOAA, Seymour 2 N, IN).

Last spring frost: April 16
First fall frost: October 21
Growing season: 187 days
Hardiness zone: 6b

First snow: December 17
Last snow: March 10
Winters with snow: 95%
Snow per year: 8"

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Frost risk by date in Seymour

Half of springs at Seymour 2 N, IN see their last 32°F night by April 16; only one in ten is past it by April 2, and one in ten still has one after May 2. Planting tender crops after April 23 leaves a 30% risk of a frost on them, after April 26 20%, and after May 2 10%. The 16 days between the even-odds date and the one-in-ten date is narrower than at 35% of the 125 Indiana stations behind this site's ZIP pages.

In fall the first 32°F night comes by October 21 in half of years, as early as October 7 one year in ten, and holds off past November 1 one year in ten. A hard freeze of 28°F follows 11 days later, around November 1; in spring the one-in-ten date for 28°F is April 19, 13 days before the 32°F one. The freeze-free season lasts 187 days in a typical year, longer than at 66% of the 125 Indiana stations; it reaches 206 days one year in ten and falls short of 166 one year in ten. On average 117 nights a year drop to 32°F or below. Nights of 36°F, when frost can still settle on leaves in low, open spots, continue 11 days longer, to about April 27, and return around October 12. Severe cold of 16°F or below comes every winter, usually between December 6 and March 1.

Spring: the chance of another night this cold after the date
Low	90%	80%	70%	60%	50%	40%	30%	20%	10%
36°F	Apr 14	Apr 19	Apr 22	Apr 24	Apr 27	Apr 30	May 3	May 6	May 12
32°F	Apr 2	Apr 6	Apr 10	Apr 13	Apr 16	Apr 20	Apr 23	Apr 26	May 2
28°F	Mar 19	Mar 24	Mar 29	Mar 31	Apr 2	Apr 5	Apr 8	Apr 13	Apr 19
24°F	Mar 4	Mar 11	Mar 16	Mar 19	Mar 23	Mar 26	Mar 31	Apr 2	Apr 7
20°F	Feb 23	Feb 28	Mar 4	Mar 8	Mar 12	Mar 15	Mar 19	Mar 23	Mar 29
16°F	Feb 9	Feb 16	Feb 22	Feb 27	Mar 1	Mar 5	Mar 10	Mar 13	Mar 19

Fall: the chance the first night this cold has come by the date
Low	10%	20%	30%	40%	50%	60%	70%	80%	90%
36°F	Sep 30	Oct 4	Oct 6	Oct 9	Oct 12	Oct 14	Oct 17	Oct 20	Oct 24
32°F	Oct 7	Oct 12	Oct 16	Oct 19	Oct 21	Oct 23	Oct 26	Oct 29	Nov 1
28°F	Oct 19	Oct 23	Oct 26	Oct 29	Nov 1	Nov 2	Nov 5	Nov 8	Nov 14
24°F	Oct 30	Nov 2	Nov 5	Nov 8	Nov 12	Nov 15	Nov 18	Nov 24	Dec 1
20°F	Nov 8	Nov 13	Nov 17	Nov 22	Nov 26	Nov 30	Dec 3	Dec 7	Dec 16
16°F	Nov 18	Nov 25	Dec 1	Dec 3	Dec 6	Dec 11	Dec 17	Dec 22	Dec 29

Freeze probabilities 1991–2020 at Seymour 2 N, IN, from NOAA NCEI U.S. Climate Normals. Where a temperature is reached in fewer than 99.5% of years, the dates describe only the years that reach it. Not a forecast.

Frost risk on any date in 47274 →Compare Seymour with another place →

Frost risk through the year in Seymour

Frost curve for Seymour, Indiana (Seymour 2 N, IN, NOAA 1991–2020): the chance of another 32°F night falls from 90% on April 2 to 50% on April 16 and 10% on May 2; the chance that the first fall one has come rises from 10% on October 7 to 50% on October 21 and 90% on November 1. — In Seymour, the spring curve drops under 10% on May 2 and the fall curve passes 10% on October 7, 158 days later; that gap is longer than at 63% of the 125 Indiana stations with frost dates. The spring risk falls from 90% to 10% over 30 days (April 2 to May 2) and the fall risk climbs from 10% to 90% over 25 days (October 7 to November 1): both ends of the season vary about as much. At Columbus, IN, 14 miles north, the same gap runs from April 30 to October 12, 7 days longer.

Chance of a frost after each planting date in Seymour
Planted on	Another 32°F night	28°F night
Apr 2	over 90%	50%
Apr 9	73%	28%
Apr 1650% date	50%	15%
Apr 23	30%	under 10%
Apr 30	13%	under 10%
May 7	under 10%	under 10%

Weather by month in Seymour

July is the warmest month at Seymour 2 N, IN, averaging 85°F by day and 64°F at night; January is the coldest at 38°F and 22°F. A freezing night is all but certain in every month from November to April (a 90% chance or more). From June to September the chance of a 32°F night stays under 10% each month. In spring, May still brings one in 13% of years.

Warmth for growing adds up to 3,496 growing degree days a year (base 50°F), more than at 60% of the 125 Indiana stations. 37% of them (1,287) have built up by the end of June, and July adds the most, 761. Precipitation totals 49.6 inches a year, most in April (5.4") and least in February (3.1"); May to September bring 45% of it.

Monthly normals 1991–2020 at Seymour 2 N, IN
Month	High °F	Low °F	Precip. in	32°F night	Nights ≤ 32°F	GDD 50°F
Jan	38	22	3.4	100%	26	5
Feb	42	24	3.1	100%	23	6
Mar	52	32	4.3	100%	18	49
Apr	65	42	5.4	92%	5	168
May	74	53	5.4	13%	<1	415
Jun	82	61	5.0	0%	0	645
Jul	85	64	4.2	0%	0	761
Aug	84	62	4.3	0%	0	711
Sep	78	54	3.4	2%	<1	489
Oct	67	42	3.6	87%	5	196
Nov	53	33	3.7	100%	16	44
Dec	42	26	3.8	100%	24	9

Monthly normals 1991–2020 at Seymour 2 N, IN (570 ft), NOAA NCEI. "32°F night": chance of at least one in the month. GDD: growing degree days, base 50°F.

Compared with the next station

The nearest other station, Columbus, IN, 14 miles north of Seymour, has a last frost 5 days earlier (April 11), a first frost 4 days later (October 25), a season 8 days longer.

Frost dates for 47201 (Columbus) →

When it snows in Seymour, Indiana

The first measurable snow (0.1 inch or more) in Seymour usually arrives around December 17, and the last of the season around March 10. Those are the middle dates across the winters of 1991–2020 at Seymour 2 N, IN, 1.6 miles away: half of years saw snow earlier, half later. Snow fell in 95% of those winters. The last 32°F night of spring typically comes 37 days after the last snow.

Planting calendar for 47274

What to do and when, from the 50% frost dates for Seymour, Indiana
When	What to do
February 5 – February 19	Start peppers and aubergines indoorsThey need eight to ten weeks under lights before they can go out.
February 19 – March 5	Start tomatoes indoorsSix to eight weeks gives a transplant big enough to set fruit early.
March 19 – April 2	Sow peas, spinach, lettuce, radish outdoorsThese tolerate light frost and prefer to germinate in cool soil.
April 16 onward	Transplant tomatoes, peppers, basil, squash, cucumbersThe average last freeze has passed — still watch the actual forecast.
by July 29	Sow the autumn crop of carrots, beets and brassicasThey need about twelve weeks to size up before growth stops.
by October 7	Harvest tender crops, or be ready to cover themA first freeze two weeks early is well within normal variation.
October 21 onward	Plant garlic, mulch beds, lift tender bulbsGarlic wants a cold spell; bare soil loses structure over winter.

The weeks before and after the 50% dates are general rules of thumb, not NOAA figures; a seed packet gives the timing for each variety.

Where these figures come from

ZIP 47274 is 2 miles from Seymour 2 N, IN, which stands at 570 feet, the nearest NOAA station that publishes freeze probabilities for 1991–2020. 1 other ZIP code shares the station. The 2023 USDA Plant Hardiness Zone Map lists ZIP 47274 in zone 6b, the band where the coldest night of the year averaged -5 to 0°F (-20.6 to -17.8°C) over 1991–2020; a zone describes winter lows, not frost dates.

Frost dates across Indiana →

Hardiness zone and temperature range: USDA Plant Hardiness Zone Map 2023 (USDA-ARS, Oregon State University), ZIP-code listing, unchanged. °C converted from °F by this site.

Thirty-year averages, not a forecast: check the forecast before planting out. How stations are matched and which pages are offered to search engines: methodology.

ZIP codes measured at the same station

47220Brownstown